I don't think so. This project has seems to have settled on the Peerless 12" woofer. The other thread is leaning toward a higher performance and higher priced woofer. The quality and character of the woofer is a dominant contributor to the sound of the speaker.
No changes, I think having the midrange measurements all comparable is the most important thing right now.
A note on SPL. I did not measure my exact voltage but I do have the SPL calibrated pretty accurately. I measured the SB26STAC first and adjusted my output levels until it was very close to the manufacturer's data sheet in the 2-4kHz area. I don't think it is particularly important that your SPL is accurate for our current decisions, but wanted to let you know that I had tried to at least make mine reasonably accurate.
A note on SPL. I did not measure my exact voltage but I do have the SPL calibrated pretty accurately. I measured the SB26STAC first and adjusted my output levels until it was very close to the manufacturer's data sheet in the 2-4kHz area. I don't think it is particularly important that your SPL is accurate for our current decisions, but wanted to let you know that I had tried to at least make mine reasonably accurate.
I will take these measurements this weekend.
Just to make sure...these nearfield measurements are free-air correct? Not in my prototype baffle and not in any kind of enclosure?
I usually make near field measurements in an enclosure. If not the final enclosure, then something relatively representative of what the final enclosure will be.
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No one has actually measured a SLS 12" vs something like a SB34RNXL, either via ESS or FSAF, so I'm going to keep an open mind and reserve judgement until I see some evidence.
Those are in completely different classes, imo.
I don't have any SLS12 but have both SLS10 and SLS8, and the SBA 10"s and several 12" SBAs. The latter have strong cast frames, stiffer cones, 11mm Xmax, and are hard to bottom out with deep bass even at pretty high volume.
The SLS 10 has much lighter stamped steel frames, less rigid cones, 8mm Xmax, and can be bottomed out with with heavy bass at moderately loud volume. Weighs about half of the SBA10. The SLS12 has the same motor, Xmax etc.
But you could say they are both good value -- the SLS is a v. good budget driver; the SBA is a mid-price driver that performs above its class.
I personally would not bother comparing them with measurements. If I can afford the SBA, I'd choose it every time.
Well I wouldn't be so fast do discount it. Although I agree that things like longer x-max and and bumped back plates can increase overload limits, we might be assuming to much when about cast frame or stiffer cones - they actually may actually windows dressing.
The reason I say this is because I actually have some drivers with plastic frames, or ordinary soft or hard cones that are top performers in their size class.
In fact, one of our friends recently wrote to me to say that he's had a driver that he thought sounded great, but didn't measure it until decades later- and it measured great. If only he knew back then what he knew now, perhaps he would have purchased a caseload!
Here's a simulation of a SLS12 12" in a 60L box vs the SB34NRXL-8 in a 60L box:
For the application of 60L closed box, the differences are less than what the price or appearance might lead us to believe.
The real benefits would be observable in a different application eg. smaller ported enclosure...
The reason I say this is because I actually have some drivers with plastic frames, or ordinary soft or hard cones that are top performers in their size class.
In fact, one of our friends recently wrote to me to say that he's had a driver that he thought sounded great, but didn't measure it until decades later- and it measured great. If only he knew back then what he knew now, perhaps he would have purchased a caseload!
Here's a simulation of a SLS12 12" in a 60L box vs the SB34NRXL-8 in a 60L box:
For the application of 60L closed box, the differences are less than what the price or appearance might lead us to believe.
The real benefits would be observable in a different application eg. smaller ported enclosure...
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I don't discount it; I'd use it if I needed to build a cheaper 3-way. (Tho the SLS 10 is actually more appealing because it does so well in a very small sealed box.) But you were asking about comparing it vs the SBA. If I built systems optimized for each driver, I have no doubt I'd hear the measured difference easily & clearly, especially at higher volume. (I did between dual SLS 10s vs dual SBA 10s.)
I like it too:
Here’s my simulation and measurement:
Was this in the same alignment and EQed for the same frequency response?
Did you, by chance, get to place the woofers in the same position and listen to them in a blinded fashion?
Yes & yes, but not blinded. The SLS bottom out way sooner. The 3mm Xmax difference in factory specs between them seems too small.
Edit: the Peerless woofers generally sounded a bit woolier, like they had higher distortion, which I think I measured too, but can't be certain of that, memory is fuzzy. Didn't save all the measurements.
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The difference between stamped steel and cast frames is significant when it comes to the mechanical side. One can expect a low cost stamped steel frame to have one or two more issues w.r.t. resonances and possibly stiffness. On the other hand the 3 kg vs 9 kg difference in weight means a high stiffness approach for the woofer cabinet design may not be viable (assuming the woofer and midrange are isolated from each other which they likely won't be in the design here). Makes a hiqh quality cabinet design challenging given the large surface area radiating directly at the listener.
Is the Peerless being looked at due to availability world wide? The Dayton RS270 is really nice, but might not be available everywhere for a reasonable price.
30% - that looks like a major improvement. 10 years ago when involved a similar group project for a similar large budget 3 way the Dayton ST-305 looked a good candidate in being a step up from the lightweight budget 12" drivers for a modest increase in price to $94.80. In Europe at the time the price from the German importer converted to dollars was $200.04. A 110% increase in price. I think the driver was manufactured in the US possibly by Eminence(?) rather than in Asia. Whatever, the Dayton ST woofers don't seem to be around anymore.
I’ve been following along here for a while as this is the sort of speaker I’d like to build next. I was planning to use the drivers I currently have in my old KLH317 cabinets, the Peerless SLS 10” and Morel CAT298 tweeters, although I also have some Vifa D27s and a pair of Chinese B1 tweeters I bought when I couldn’t get anything else here during Covid.
I am very interested to see where we end up on the midrange. I had planned to use a Monacor SPH-135C as I had a spare and thus only needed to buy one more, but sadly these are NLA. The similarly sized Monacor units are a bit expensive, but I like the look of the SPH-145HQ.
I do have some Visaton W100S I could use, but these are only 4” and 4 ohm types.
I am still in early days of speaker building, so it might be nice to try the SS15s. Following with interest here!
I am very interested to see where we end up on the midrange. I had planned to use a Monacor SPH-135C as I had a spare and thus only needed to buy one more, but sadly these are NLA. The similarly sized Monacor units are a bit expensive, but I like the look of the SPH-145HQ.
I do have some Visaton W100S I could use, but these are only 4” and 4 ohm types.
I am still in early days of speaker building, so it might be nice to try the SS15s. Following with interest here!
Full disclosure: the application was only bass below 120 Hz in W-frame OB. I don't know how they compare run up to say 600Hz. Never listened to either SLS10 or SBA10 that high up.
Just FYI, in the KLH317s the 10” runs up to ~2KHz. (First order xo).
In case anyone needs confirmation, no, this isn’t a good idea and doesn’t sound good.
In case anyone needs confirmation, no, this isn’t a good idea and doesn’t sound good.
Here is the evaluation of the SB12MNRX2-25-4 that I had on hand.
First I will describe the test box I built.
I matched the baffle dimensions provided by @A4eaudio. The driver was loaded with a 2.9 l sealed box with internal dimensions of 2.25" x 7.5" x 10.25". The mid driver was centered horizontally, and 9" down from the top edge. The plywood test baffle was available from another project, so I incorporated it here. When I made the test baffle, I cut the recess slightly large. I used modelling clay to fill/smooth the gap between the driver and the recess.
Below is the near field scan of the driver in the test box. Because the driver is so small, with an Sd of only 50 cm^2, the NF data is valid up to 1400 Hz. The data looks nice and smooth, and no resonances were detected.
Below is the impedance data. Again, no box resonances (either structural or acoustic) were detected, so I concluded that the test box was functional and suitable for evaluating this driver.
There is a small burble in the impedance curve between 1.5k and 2.1k.
The above burst decay plot was processed from the near field impulse, so again I only show it up to 1.4k. Nothing going on below 1k, but at about 1.2k we start to see some stored energy. Whatever is there is very well damped, so I suspect it is the rubber surround. Regardless, it is very minor.
(more to come)
First I will describe the test box I built.
I matched the baffle dimensions provided by @A4eaudio. The driver was loaded with a 2.9 l sealed box with internal dimensions of 2.25" x 7.5" x 10.25". The mid driver was centered horizontally, and 9" down from the top edge. The plywood test baffle was available from another project, so I incorporated it here. When I made the test baffle, I cut the recess slightly large. I used modelling clay to fill/smooth the gap between the driver and the recess.
Below is the near field scan of the driver in the test box. Because the driver is so small, with an Sd of only 50 cm^2, the NF data is valid up to 1400 Hz. The data looks nice and smooth, and no resonances were detected.
Below is the impedance data. Again, no box resonances (either structural or acoustic) were detected, so I concluded that the test box was functional and suitable for evaluating this driver.
There is a small burble in the impedance curve between 1.5k and 2.1k.
The above burst decay plot was processed from the near field impulse, so again I only show it up to 1.4k. Nothing going on below 1k, but at about 1.2k we start to see some stored energy. Whatever is there is very well damped, so I suspect it is the rubber surround. Regardless, it is very minor.
(more to come)